The blaze occurred around 10 p.m. PDT on westbound lanes of the bridge, which connects San Mateo and Alemada counties, about 20 miles southeast of San Francisco.

The patrol said that smoke started coming out of the rear of the limo, and the driver pulled over as the vehicle quickly became engulfed in flames.

"We have no idea right now where they were going or where they were coming from," Jack told the station.

Of the survivors, Jack said one had severe burns and three others suffered minor to moderate injuries that included smoke inhalation. The four were rushed to nearby hospitals for treatment, while the fifth person who escaped wasn't hospitalized.

The status of the driver wasn't immediately clear.

Several lanes of the bridge were closed as officers investigated the cause of the deadly fire, but the patrol said one lane of traffic reopened early Sunday.